The present invention relates to a control apparatus for controlling an occupant protection device of a vehicle, such as an airbag and seat-belt tensioner.
A conventional control apparatus for controlling an occupant protection device, as shown in The Japanese Patent Laid Open Publication No.8-85414, for example, has an acceleration sensor provided on a floor tunnel in a car room. The acceleration sensor detects an acceleration operating to a car body through the floor tunnel, and gives an analog signal representative of the acceleration to the control apparatus. The control apparatus integrates the acceleration signal from the acceleration sensor, detects an occurrence of a collision requiring a drive of an occupant protection device based on a comparison between an integrated value of the acceleration signal and a predetermined collision decision threshold value, and drives the occupant protection device such as an airbag.
By the way, when an impact of collision is absorbed by a crush of a collision part of the car body, it can be assumed that a collision acceleration transmitted to the floor tunnel is weakened. In such a case, since an acceleration detected by the acceleration sensor provided on the floor tunnel is small, though there is no fear of it causing difficulties in occupant protection at time of collision, a fear of causing a delay in driving the occupant protection device exists. In particular, a collision, such as an offset collision or an oblique collision, tends to cause a case in which the acceleration transmitted to the floor tunnel is weakened. Because of this, from the viewpoint of improving a control of the occupant protection device, regardless of whether the collision acceleration transmitted to the acceleration sensor provided in the car room is weakened, an exact control of the occupant protection device is desired.